Appaeatus foe smelting and eefining coppee



(No Model.) 3 She'ets-Sheet 1. J, a. BULL. APPARATUS FOR SMELTING AND BEFINING COPPER.

No. 520,631. Patented May 29, 1894.

.fil lelii'orr Jizmmes 6,8151% JZ/W 3 Sheets-Sheet 2.

(No Model.)

J. 0. BULL. APPARATUS FOR SMELTING AND REPINING- COPPER.

Patented May 29, 1894.

(No Model.) a Sheets-Sheet 3.

J. G. BULL.

APPARATUS FOR SMBLTING AND REPINING COPPER. No. 520,631. Patented May 29, 1894.

zit/285.505: haw/mar. M A JmmzwQ Baza UNITED STATES PATENT E EICE.

J OHANNES G. BULL, OF ERITH, ENGLAND.

APPARATUS FOR SMELTING AN D REFINING COPPER.

SPECIFICATION forming part of Letters Patent No. 520,631, dated May 29, 1894.

Application filed May 12, 1891- Serial No. 392,498. (No model.)

To aZ Z whom it may concern.-

Be 1t known that I, J OHANNES CATHARINUS BULL, engineer, a' subject of the King of Sweden and Norway, residing at Erith, in the county of Kent, England, have invented certain new and useful Improvements in Apparatus for Smelting and Refining Copper, of which the following is a specification, reference being had to theacco'mpanying drawings.

My invention relates to improvements in apparatus for the smelting and refining of copper obtained from ores, mattes or other cupriferous materials by oxidation which is attained by the introduction of nitrates or other similar substances into the copper below the surface thereof while the metal is in a meltlng or molten state in measured and controllable quantities and at a controllable speed.

In order that my invention may be more easily understood I will describe the same with reference to the accompanying drawings, of which- Figure 1 is a sectional elevation of a convertersomewhat after the style of a Bessemer converter and suitable for refining small quantitres of copper say three or four hundredwelght at a time. Fig. 2 is a similar view of a converter adapted for working on a some what larger scale. Fig. 3 is a sectional eletlon of apparatus which I prefer to use in working my invention commercially. Fig. A 1s a sectional plan view on line X Y Fig. 3, and Fig. 5 is a side elevation partly in section on line Z Z Fig. 3.

The same letters of reference refer to similar or equivalent parts in all the drawings. I I prefer to use as shown on the drawings a furnace or converter Aof the Bessemer converter type provided with trunnions d to allow of inversion.

Referring more particularly to Fig. 1, the bottom part a can be bolted or otherwise fixed onto the converter A. I prefer to make the lining A of. the converter and the bottom part of ganister or other suitable fireproof material such as a mixture of sand and clay. In thebottom part a of the converter A is firmly embedded an open'vesselb with a conical or other suitably shaped upper part or top 0, both made of fire clay or other refractory material. The top 0 has a number of holes 0,

say from ten to fifteen,of a diameter of from one-fourth to three-eighths of an inch. The conical top 0 of the vessel 1) has the same taper as a metal fin a formed on the bottom of the converter and the lining A thereof after the point when the said fin a ceases, so that the top 0 is kept in place by the fin and the lining when the bottom part a is fixed in its place.

In using this form of converter or furnace I proceed as followsz-Into the vessel b I introduce oxidizing agents such as nitrate or chlorate of soda or potash, the cover 0 is then put on and thebottom part a is fixed in its place at the bottom by. means of bolts as shown or in any other convenient manner. The weight of the charge of nitrate of soda corresponds to about five per cent. of that of the copper intended to be refined and in these proportions good results have been obtained. It should however be noted that the amount of oxygen produced by different oxidizing agents varies and the proportions have to be varied to suit difierent cases and that wherever the expression nitrate is used herein it should be understood that any suitable oxidizing agent is intended. The impure copper is melted with a suitable slag for the scorification of ferrous and other oxides while in the converter and is then poured into the said converter A whereupon a portion of it will sink through holes 0 into the vessel b, and by the intense heat, decompose part of the nitrate and cause a strong current of oxidizing gases or matter to pass up and through the molten copper which gases for a time exert sufficient pressure to prevent further quantities of the copper from entering the vessel b. After a while however the pressure decreases so that more copper can enter through the lowest holes 0', more gases are disengaged and the process is continued until all the nitrate or other oxidizing agent in the vessel 1) is decomposed. The number and size of the holes 0' are so arranged that the speed of the decomposition is regulated. During the process the iron is oxidized and scorified by the slag which should be rich in silica, the sulphur is oxidized and removed as sulphurous oxide, the arsenic and antimony are oxidized and volatilized at the high temperature developed and the other impurities are either gasified or scorified by the'slag or the lining. When the reaction becomes languid the slag may be removed through the opening closed by a door f and the copper, after. poling, tapped through an opening g or it may be poled outside the converter, or if as shown the converter be invertible the copper may be poured out through its mouth. The bottom part a is then detached and any copper that may remain in the vessel b is emptied out, a new charge of oxidizing agent inserted and the process repeated as before described.

When it is required to treat larger quantities the arrangement shown in Fig. 2, Sheet 1, may be conveniently employed. The ves sel b in this case is replaced by a conical block 0 made of the same material and se cured in place by the fins a as before described. This block a has a horizontal channel o with six or more vertical tapering passages or holes 0 as shown. The channel c is in communication with a tube is which is embedded in the lining of the converter and is provided on the outside of the converter with a stop valve or cook Z for opening and shutting ofi communication with the tube Zwhich is lagged or covered with non-conductin g material. The tube Z is carried up above the level of the copper in the converter and communicates with a vessel 1) which is also preferably lagged or coated with non-conducting composition. The vessel Z) is provided with a lamp or other heat producer at. The oxilizing agents are introduced into the vessel 0 and melted by heat in a convenient manner and as the impure molten copper is poured into the converter, an air pump 0 is put in motion, the valve Z opened and by the air pressure on the surface of the liquid or semi liquid nitrate, jets of the latter are forced into the copper through the holes 0' at such a rate that about five per cent. of the nitrate compared with the weight of the copper is forced in during a period of from ten to fifteen minutes, providing the copper do not contain more than from five to eight per cent. of impurities. The period is of course extended if thepercentage be higher. If the supply of oxidizing agent contained in the vessel 1) be not sufficient for the amount of copper contained in the converter, I may, in order not to interrupt the process provide duplicate parts for the supply of the oxidizing agents or as shown the vessel 1) may be connected to another similar vessel situated at a higher level and connected thereto by a pipe 19 having a cook or valve 10, the valve Z being closed during the refilling of the vessel to prevent the copper rising in the tube Z and opened when sufficient oxidizing agent is obtained ready for the continuation of the supply thereof. Otherwise this form of apparatus works in the same manner as that described with reference to Fig. 1 with this exception that the supply of the nitrate or other oxidizing agent is under better control. If the converter or furnace be of the invertible typethe supply pipe Z is led through the trunnion. The poling must either take place outside the converter or while the latter is laid over so far that the metal cannot enter the channelsc'. About eight or ten hundred weight is a suitable charge for a furnace of this description.

The reason for making the inside bottom of the converter of the approximately coned form shown is that a better distribution of the oxidizing agent is effected while at the same time where required facilities are given for the purest grade of copper to sink below the level of the holes 0' and the said copper may when desired be easily'drawn off by an opening 9 normally closed by a plug.

When working on a large scale and particularly when treating matte, regulus t or coarse copper with large percentages of 1mpurities I prefer to use a converter constructed on the lines of an ordinary Bessemer converter being however modified to a certain extentto adapt it to the work in question, as shown with reference to Figs. 3 and 4:, Sheet 2, and Fig. 5, Sheet 3. In this case have shown a method of supplying the oxidizing agent in a dry and powdered form by means of a blast. A vessel 1) is filled with the powdered nitrate and closed with a lid 19' either screwed or sufficiently heavyto prevent lts being raised by the pressure of the blast. In the bottom p2 rt of the said vessel I mount a wheel b provided with a number of pockets or series of revolving hoppers which wheel 1s revolved at a controllable speed by any suitable means and thus regulates the amount of powdered nitrate to be discharged from the vessel 1) into the pipe Z by means of the blast coming from any suitable source by the pipe 0. The Wheel b is fitted to work tightly against the walls of the vessel 1) so that no appreciable amount of blast can pass it into the vessel b. I may however also provide a by pass pipe b in order to equalize the pressure above and below the nitrate in the vessel b. By' regulating the speed of the wheel b which is actuated preferably by worm and Worm wheel gear, the amountof powdered nitrate can be accurately controlled. If the copper to be refined contains less than eighty per cent. of metallic copper, say fifty to sixty per cent., the process should proceed as foilows:-A suitable charge of say two thousand five hundred to three thousand pounds is melted with some slag rich in silica and poured into the converter in the usual way and the blast is put on, the atmospheric air alone being sufficient to oxidize the impurities at a sufficientrate to keep the metal fluid for some time, but partly to accelerate the reactions and partly to keep the tuyeres 0' clear and open it is advisable to start the nitrate feeding apparatus at once at a slow rate, the nitrate decomposing at the openings and acting on the impurities of the copper sufiicient heat is evolved to make it sure that the openings do not become choked. To further assist this clearing action I make as shown one or more of the cells or hoppers of the wheel 19 with a larger capacity than the others thus generating a larger quantity of gases and consequently a great evolution of heat at suitable intervals. During the first fifteen to twenty minutes about one and onehalf per cen t. of nitrate should be introduced after which the converter is turned over so far that the slag can be removed, the blast stopped or reduced, fresh slagintroduced and the blast continued as before for anotherfifteen or twenty minutes with an injection of two to four per cent. of nitrate, increasing the speed of injection as the amount of impurities and consequently the heat evolved through their combustion diminishes. When the absence of flame and smoke or vapor denotes the end of the process, the metal is poured after poling unless the latter process is carried on outside the conv'erter. With metal having about eighty per cent. or more of metalllc copper or when the converter is fixed the process is carried on without interruption to the end. When the matte is very poor it may be necessary to pour out the Chili saltpeter (nitrate of soda) as being the cheapest and not too violently explosive when subjected to heat but other materials capable of evolving large quantities of oxygen or oxidizing gases or matters or mixtures thereof may be employed. The mattersreferred to may also be decomposed by heat or otherwise outsideof the apparatus and the resulting bodies or gases evolved forced in in any suitable manner.

I have only described and shown apparatus for carrying on the refining process intermittently but it is evident that the latter might be made continuous by passing the refined copper out at'the bottom while feeding in the molten unpurified metal.

.Having fully described my invention, what I desire to claim and secure by Letters Patent is- An apparatus for refining copper comprising a converter and in combination therewith of a vessel or holder seated centrally in the bottom lining thereof and having a conical top projecting into the converter above said bottom, the top of said vessel beingprovided with diverging passages, substantlally as and for the purpose set forth.

in combination with a chambered cone seated in said bearing and projecting beyond the same into the converter, said cone having diverging passages formed in and about its apex, andretaining devices connected with the convertershell havin gbearing on the sides of the chambered cone, substantially 'as and for the purpose set forth.

4. An apparatus for refining copper comprising'a converter, a chambered cone projecting centrally from the converter bottom into the same, said cone provided in and aboutits apex with diverging passages, atap hole in'the converter wall below the apex of said cone, a receiver for containing an oxidizing agent, a connection between the receiver and the chambered conical bottom of the converter, and a forcing device for forcing the oxidizing agent into and through said chambered bottom, for the purpose set forth.

5. An apparatus for refining copper comprising a converter having the central portion of its bottom constructed inthe form of an inwardly projecting cone, said cone being chambered and provided in and about its apex with diverging passages, a receiver for holding a dry pulverulent oxidizing agent, a pipe connection between the receiver and the chambered bottom of the converter,afeeding device constructed to feed the oxidizing agent in measured quantities to said pipe connections and a blast pipein communication with the pipe'connections, substantially as and for the purpose set forth.

J. O. BULL.

Witnesses:

THOMAS LAKE,

17 Gra'cechurch Street, London. ARTHUR M. FLAOK,

77 Chancery Lane, London. 

